Update containerd to v1.2.7

From the release notes: https://github.com/containerd/containerd/releases/tag/v1.2.7

> Welcome to the v1.2.7 release of containerd!
>
> The seventh patch release for containerd 1.2 introduces OCI image
> descriptor annotation support and contains fixes for containerd shim logs,
> container stop/deletion, cri plugin and selinux.
>
> It also contains several important bug fixes for goroutine and file
> descriptor leakage in containerd and containerd shims.
>
> Notable Updates
>
> - Support annotations in the OCI image descriptor, and filtering image by annotations. containerd/containerd#3254
> - Support context timeout in ttrpc which can help avoid containerd hangs when a shim is unresponsive. containerd/ttrpc#31
> - Fix a bug that containerd shim leaks goroutine and file descriptor after containerd restarts. containerd/ttrpc#37
> - Fix a bug that a container can't be deleted if first deletion attempt is canceled or timeout. containerd/containerd#3264
> - Fix a bug that containerd leaks file descriptor when using v2 containerd shims, e.g. containerd-shim-runc-v1. containerd/containerd#3273
> - Fix a bug that a container with lingering processes can't terminate when it shares pid namespace with another container. moby#38978
> - Fix a bug that containerd can't read shim logs after restart. containerd/containerd#3282
> - Fix a bug that shim_debug option is not honored for existing containerd shims after containerd restarts. containerd/containerd#3283
> - cri: Fix a bug that a container can't be stopped when the exit event is not successfully published by the containerd shim. containerd/containerd#3125, containerd/containerd#3177
> - cri: Fix a bug that exec process is not cleaned up if grpc context is canceled or timeout. contaienrd/cri#1159
> - Fix a selinux keyring labeling issue by updating runc to v1.0.0-rc.8 and selinux library to v1.2.2. opencontainers/selinux#50
> - Update ttrpc to f82148331ad2181edea8f3f649a1f7add6c3f9c2. containerd/containerd#3316
> - Update cri to 49ca74043390bc2eeea7a45a46005fbec58a3f88. containerd/containerd#3330

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/dockerfile/install/containerd.installer

@@ -4,7 +4,7 @@
 # containerd is also pinned in vendor.conf. When updating the binary
 # version you may also need to update the vendor version to pick up bug
 # fixes or new APIs.
-CONTAINERD_COMMIT=894b81a4b802e4eb2a91d1ce216b8817763c29fb # v1.2.6
+CONTAINERD_COMMIT=85f6aa58b8a3170aec9824568f7a31832878b603 # v1.2.7
 
 install_containerd() {
 	echo "Install containerd version $CONTAINERD_COMMIT"